Traditionally, huge amounts of information have required carefully cataloguing by a manual process in order to make it retrievable. The information is accessed by means of the manually added metadata.
As the Internet emerged, the initial mode of access was via directories that manually classify pages and sites on the Internet. These directories, such as Yahoo (www.yahoo.com) and the Open Directory Project (www.dmoz.org), still exist, but as the content volume grows faster than the capacity of manually classifying content, these directories are replaced or complemented with search-based information access patterns based on information retrieval methods.
Web directories have been generalized to portals. A portal presents information from a variety of sources, including typical non-Internet content, e.g. relational databases, applications, all within a consistent framework for the developer, look and feel for the consumer, and a unified security model across all sub-systems exposed as single sign-on to the information consumer and with corresponding content entitlement. Enterprise portals are commonly used to integrate a range of internal and external enterprise systems and data repositories.
A page in the portal is composed of several portlets, where a portlet represents the information from a single source. The developer states rules for which portlets are to appear on what page and where on the page they are to appear. The presentation can also be targeted to presentation devices, e.g. the limited screen estate on hand-held devices. Several big software companies provide portal products for the system integration. (For more information, see http://www-128.ibm.com/developerworks/ibm/library/i-portletintro/)
When an information consumer accesses information, the query is more or less explicit. The consumer can spell out a query if a suitable device is at hand. On a mobile device with limited textual input, it is desired to reduce the burden to spell out long queries. The context of the user as information is sought contributes implicitly to the query. For example, the query can be implicitly extended and directed to appropriate content depending on whether the user is at home or at work. The position of the consumer can give clues to what geospatial content is relevant.
The integration of search in a portal framework may simply choose to use a single portlet for the search. A more advanced integration makes separate portlets for the search box, the result list, and each of the navigators.
The presentation of query feedback (spelling suggestions, definitions, etc), the result list, and navigators in a portal framework is subject to rules specified by the developer. The size, position, and order are defined manually in advance based on assumptions and generalizations, optimizing the consumer experience for the least work required by the developer.
Discussion of the Problem
A portal aims to be the central point for any information requirement. By nature, it has to care for a wide range of information needs, for example high-level content aggregation and overviews, lower level knowledge investigation, specific fact finding, and retrieving a specific document the user has in mind.
Generally, the portal designer anticipates a pattern of use cases and defines a common layout across all use cases. At best, a few use cases have been identified that are central to the enterprise, and separate user interfaces have been geared towards these scenarios. Each of these tailor-made interfaces requires a significant amount of investment in identifying, developing, and testing the application logic and the usability of the presentation.
Thus, the user interfaces are based on crisp rules on what information components (portlets) are included, where they are positioned, and the presentation size. The rules are typically based only on user attributes, e.g. access rights, interest group, office location, and possibly on the device type. For example, a huge or client specific portlet may only be viewed on devices with sufficient screen estate. In general, it is hard and expensive to define one presentation layout that covers all information needs, and general layouts give unsatisfactory usability.
When screen estate is limited, it is hard to make correct a priori selections of portlets. The user may easily find it very hard to access the desired information as the correct elements for the given context are not included on e.g. a small hand-held device.
On large screens, however, portals tend to suffer from information overload. The portal designer incorporates a lot of content in order to increase the likelihood of presence of some appropriate content, and the content consumer experiences information overload. The consumer has to scan pages that are visually complex: there are many components of different structures and the pages may span several screens on the device. This cognitive distillation of the alternative information components is a stress factor for humans.
FIG. 6 is an example of an information presentation that suffers from information overflow. A user carrying out a task will need considerable time to digest the information in order to build a mental model of the structure of the presentation and the information within it. In many tasks involving search, users are not prepared to operate in such a mode. They expect the required information at most a few clicks away and within a few seconds. The presentation in FIG. 6 specifically suffers from too many content components (screen elements) and that several of the content components stretch beyond the current view.
Specifically in search systems, navigators are used to refine or otherwise manipulate search results in a user-friendly manner. However, on any result screen there is only space for a few navigators. While the available set of meta-data is very large, the choice of the best navigators is often limited, static and suboptimal. Navigator selection is either static or based on hard-coded rules applied at query time, with the risk of including irrelevant and excluding relevant navigators.
Individual navigators are often polluted by noisy elements. Low probability values are presented throughout navigators where the elements are ranked by value (e.g. with hierarchical/tree-like navigators) and at the end where the elements are ranked by probability/frequency. Such elements do not offer a likely query refinement for the end-user and should be removed (or grouped in an “other” option) in order to make the most efficient use of the presentation space. For example, there is no point in showing a drill-down option that includes 97% of the result set, even though it is the most prominent value within the current result set. Likewise, a drill-down option that includes 1% of the result set is most likely not interesting when there are three options that each account for more than 20% of the result set.
Both the physical exclusion and the information overload reduces the usability and the effectiveness of portals, resulting in reduced turnover in an e-commerce setting, customers leaving the site and reduced stickiness, reduced productivity of employees, etc.
The cost of improving the usability for specific use cases by extending the layout rules is prohibitive with current systems. Moreover, the portal frameworks are not geared towards the cooperative information coordination between portlets. The idea of independent, reusable information components is good for the portal designer but tend to contradict the ease of information consumption unless there is a common cognitive model behind the portal (and the portlets). Simply including many information views (portlets), there is no guarantee that these are orthogonal views of the content in question, and the portal designer has no support from the portal framework to judge (and define rules) to present the content most effectively on the given screen real estate.
As systems for information access, search and retrieval are becoming more sophisticated with search engines that not only search the content and present a straightforward search result to the user, but also analyze, evaluate and rank the data and moreover are able to create navigation tools offering these for a user, and hence allow for improved discovery for instance of deep and hidden structures in the information content. However, the manner of presenting the results of search and search-derived applications adheres to traditional modes of presentation that does not support user cognition and the presentation of information in a degree that matches the evolving sophistication of systems for search, access and retrieval, or advanced search engines which have been or are being developed for powering such systems. Hence there is a need for optimizing the presentation of information in a user-centric context and particularly improving the presentation for a user.